lumia 920 not working over wifi-only 3g

[chc0112]

I recently bought a lumia 920 second hand, and when I connected it to the windows store it would give me lots of error codes and not let me download apps, so I tried to update the software and it did the same thing, saying it wouldn't connect. So I tried turning the WiFi off to see if it did anything and everything worked perfectly, which is really annoying as it means I can only download apps, use Facebook and update my phone over 3g. I just tried updating the phone to the lumia amber update and the only difference was that it stopped showing specific error codes, it just didn't connect. Anyone have any suggestions?

 

[DBDev]

That sounds strange. Have you tried to restart the router or connecting to another network?